Caution: arterial line error

We would like to report a near miss in our intensive care unit. An elderly patient had an emergency, though uneventful, ruptured abdominal aortic aneurysm repair and he was transferred to the intensive care unit. Postoperatively he became hypotensive and he was thoroughly reviewed. He was sweaty, tachycardic and hypotensive but peripherally he had good capillary refill. Ventilatory parameters were unchanged. His abdomen was soft and not distended, and he had good distal perfusion with easily palpable foot pulses. An ECG was normal. His previous arterial blood gas showed a blood glucose of 16 mmol.l−1 and a worsening acidaemia. He was treated with fluid boluses and eventually noradrenaline. Blood results at this point showed a blood glucose of 2.6 mmol.l−1, not 16 mmol.l−1 as it had been previously and hypoglycaemia was treated promptly. Further assessment revealed that the arterial line transducer had been connected in error to a 500-ml bag of dextrose 4% saline 0.18% and not saline 0.9% as is standard. The writing on the fluid bag was obscured by the fabric of the pressure bag. It had not been checked when the patient returned from theatre. This caused an artificially high blood glucose reading from the arterial line. The patient came to no harm, but this is a cautionary tale, changing our local practice. Pressure bag devices with clear windows allow easy checking of fluid in invasive lines, and this should be documented on the intensive care charts at every nursing shift change.